AD is a median of the triangle ABC. Is it true that AB + BC + CA > 2AD?
Give reason for your answer.
True
Solution.
Let triangle be AB with median AD
AD is the line bisecting BC
BD = CD
sum of two sides of a triangle is greater that third side.
In ABD
AB + BD > AD …(i)
In ADC
AC + DC > AD …(ii)
Adding (i) and (ii)
AB + BD + DC + AC > 2AD
( BD + DC = BC)
AB + BC + AC > 2AD
Hence proved